Pneumatic gun for applying mortar



April 22, 1930. L. E. MccoRMAcK 1,755,329

I PNEUMATIC GUN FOR APPLYING MORTAR Filed March 14, 1927 INVENTOR ,l TATTORNEY v Aamag {Ala dbl/21M Patented Apr. 22, 1930 LAWRENCE E.MCCORMACK, F SEATTLE, WASHINGTON PNEUMATIC GUN FOR APPLYING MORTARApplication filed March 14, 1927. Serial No. 175.040.

My invention relates to improvements in apparatusof the form hereinaftertermed a mortar gun, which is adapted for applying plastic mortar towalls, and the object of my invention is to provide portable pneumaticapparatus of simple and eflicient con struction that is capable ofhandling -wet mortar and of depositing said wet mortar in an evenlayer'of any desired thickness on any wall or surface to which it isdesired to apply said mortar.

A further object is to provide a mortar gun of this nature in which themortar is carried in a portable container and the nozzle forspraying'said mortar is attached directly to the bottom of said container therebyproviding an arrangement in which the feed of the mortar is assisted bygravity and in which all hose and like conduits with the exception of asingle air line are eliminated.

Another object is to provide a mortar gun in which" several abruptshoulders and changes of area are afi'orded in the nozzle preventing aseparation of the ingredients of the mortar and insuring a furthermixing of the same. 7

A further object of the invention is to pro vide a nozzle of simple andefficient construction which is made up, for the most part, of

standard pipe-fittings and in which the parts may be readily removed forthe purpose of cleaning and replacement.

A further object is to provide a mortar gun of this nature that may bereadily carried and handled by one man and that may be convenientlyre-loaded with mortar at frequent intervals when in operation.

Other and more specific objects will be ap- P parent from the followingdescription taken connection with the accompanying drawmgs. r

In the drawings Fig. 1 is a view in side elevation of a portablepneumatic mortar applying device constructed in accordance 5 with myinvention. I

Fig. 2 is a plan view ofthe same. Fig. 3 is a View in vertical midsection of the same on a larger scale.

Fig. 4 shows a modified form of nozzle for so applying thin mortars.

Fig. 5 is a fragmentary elevation of a modification of the invention inwhich a valve is interposed between the container and the nozzle.

In the handling of mortar in a plastic state after it is mixed withwater I find that it is not practical to conduct said mortar throughhose or pipes for any substantial distance but that it is necessary todeliver the mortar directly from a container to the nozzle in order to'get a smooth and even discharge of mortar of the proper consistency tokeep the ingredients of the mortar from separating, and to handle themortar with a minimum air pressure and without clogging the passagewaysin and to the nozzle. The present invention accomplishes this purpose ina simple and efficient manner and enables me to handle mortar of theconsistency ordinarily applied with a trowel, or thinner 7 if desired,by pneumatic means.

Referring to the drawings, throughout which like reference numeralsdesignate like parts, 6 designates a mortar receptacle, preferably ofconical shape. The receptacle 6 is provided on two opposite sides withhandles 7 and is provided on-a side at right angles to said handles 7with a body rest 8 that is adapted to be placed against the body of theperson that is carrying and using the device. 30

The bottom end of the receptacle 6 terminates in a discharge opening 10that is connected by a bushing 11 and nipple 12 with a T fitting 13. Oneend of the T fitting 13- is connected by a nipple 14 with a con- Vergentdischarge fittin 15, which is, in turn, connected with a cylin ricaldischarge niple 23 the discharge end of which is flattened as at 25. Theseveral fittings and reducers of which the discharge part of the nozzleis made up serve to hold the mortar back and agitate the same mixing themortar more thoroughly and preventing the water from separating from themortar. The other end of the T fitting 13 is connected by suitablereducers 16 with an air inlet pipe 17 which connects with an air hose 18that may be connected With a suitable source of supply of air underpressure. 20 is an in'ector tube disposed axially within the" T fittmg13 and having an enlarged head 21 that is screwed into the innermostreducer member 16 and jammed tightly against the end of the air inletpipe 17. The injector tube 20 is preferably smaller than the pipe 17 andis necessarily much smaller than the T fitting 13 and the outer ordischarge end of said tube terminates within the .nipple 14. An annularspace 22 is left between the outer walls of the injectortube 20 and theinner walls of the T fitting 13 and nipple 14 through which mortar may.be drawn by suction as indicated by the arrows in Fig. 3. The outer endof the convergent nozzle 23 is flattened as at 25 to spread thedischarging mortar.

In Fig. 4 I have shown a discharge nipple 26 as provided on its outerend with a second reducer member 27 of cylindrical shape and internallythreaded to impart a whirling motion to the discharging mortar therebygiving a peculiar finish to a wall. This form of nozzle is for use inputting on finishing coats of relatively thin mortar.

In the form shown in Fig. 5 I have shown a valve 24 interposed betweenthe receptacle 6 and the nozzle member to regulate or entirely shut offthe discharge of material from the receptacle 6. For mortar of ordinaryconsistency the valve 24 is not-needed.

In the operation of this device the mortar, thoroughly mixed and readyfor application to a wall, is placed in the receptacle 6, saidreceptacle preferably being large enough to hold an ordinary'pail fullof such mortar. The operator graspsthe handles 7, letting the member 8rest against his body, directs the nozzle toward the .wall to whichmortar is to be applied and admits air under pressure through the hose18. Said air issuing from the injector tube 20 at high velocity producesa suction in the fittingv l3 and nipple 14 which draws mortar from thereceptacle 6 down through the opening 10 and sprays said mortar from theend of the nozzle 23. The mortar being driven with considerable forceagainst the wall to which it is being applied may be driven into all ofthe minute openings in such wall leaving said mortar in very compactform andcausing it to adhere very tightly to the wall. I find thatmortar applied in this way adheres much more tightly to the wall, has agreater density, is freer from air spaces, in less liable to crack andis more impervious to moisture than the same mortar applied in the usualway with a trowel. The mortar may also be applied a great deal morerapidly in this Way than with a trowel giving the mortar a betteropportunity to set evenly making it possible to use a quick settingmortar and saving much time and labor. The nozzle tip 23 being flattenedon the end as at 25 tends to spread the mortar in a fan like sheetrather than in a true cone so that when the nozzle is moved up and downthe mortar is deposited very evenly. The nozzle 23 of reduced area andthe abrupt shoulders formed by the sevformed by the rear end of thenipple 14 just back of the discharge opening of the injector tube 20 isespecially useful in distributing the mortar and producing an even fiowof the same. i

The foregoing description and accompanying drawings clearly disclose apreferred embodiment of my invention but it will be understood that thisdisclosure is merely illustrative and that such changes in the inventionmay be made as are fairly within the scope and spirit of the followingclaims.

I claim:

1. In a pneumatic mortar gun, a receptacle having a discharge opening inthe bottom end and convergent toward said discharge opening, a T fittingconnected with said bottom and forming a passageway crosswise of saiddischarge opening and communicating therewith, discharge nozzle meansconnected with one end of said T fitting, and aflording 'an abruptannular shoulder within said T fitting, a reducer fitting at the otherend of said T fitting, pressure inlet conduit means connected with saidreducer fitting, and a relatively small injector tube disposed axiallywithin said T fitting and supported by said reducer fitting andcommunicating with said pressure inlet conduit means, the discharge endof said injector tube extending beyond the inlet opening to saidreceptacle and terminating just beyond said abrupt annular shoulder.

2. In aportable pneumatic mortar gun, a funnel shaped receptacle, a Tfitting extending crosswise of the bottom end of said receptacle andcommunicating therewith, a short nipple connected with one end of said Tfitting and forming an abrupt annular I shoulder within said T fitting,a convergent pipe reducer connected with said nipple, a discharge nozzleconnected with said convergent reducer and affording at its inner .endan abrupt shoulder, said nozzle being flattened on its discharge end tospread mortar horizontally in fan shape, pipe reducer fittings in theother end of said T fitting and a relatively small injector tubearranged axially of the T fitting and supported by the I reducers andterminating within said nipple for discharging air under pressurethrough said nozzle, said fittings affording abrupt shoulders foragitation of the mortar to prevent a separation of the solid matter andwater.

The foregoing specification signed at Seattle, VVash., this 24 day ofFeb, 1927.

LAWRENCE E. MCCORMACK.

